Internal combustion engine



Dec. 5, 1933. c. H. WIEGMAN INTERNAL COMBUSTION ENGINE Filed July 21,1930 2 Sheets-Sheet l gww/Moz CLHEENEEH MEEMHN.

Dec. 5, 1933. c. H. WIEGMAN INTERNAL COMBUSTION ENGINE Filed July 211930 2 Sheets-Sheet 2 l y j m w as 16 \n \H 35 V 34 D 37 42 4 CLHEENEE[7. MEEMHN.

T 59 g i W M v Show Patented Dec. 5, 1933 UNITED STATES PATENT osslcs 11Claims. (01. 123-179) This inventionrelates to internal combustionengines and more particularly to engines of the compressiondgnition.type in which fuel is injected into the combustion chamber throughmechanism actuatedby a moving engine part.

The, invention has to do more particularly with the starting of enginesof the character described in which fuelis injected at a pressuredeveloped inaccordance with the engine speed. With this type of engine,the degree of fuel atomization and the pressure at which the fuel isinjected becomes less as the speed of the engine is reduced, and thusthefuel'is not. injected into the compressed air inthe combustion chamberat a pressure or in an atomized condition conducive to easy startingwhen the crank shaft is being turned slowly by a source of externalpower.

An object of the invention is to regulate the timing, the pressure andatomization of liquid fuel injected into compressed air in the cylindersofa compression-ignition engine so as to promote combustion when theengine is being started.

Another object of my invention is to provide an internalcombustionengine of the compressionignitiontype in which manually controlledmechanism can. be actuated to simultaneously retard the timing of thefuel injections and to increase the pressure produced by a moving partof the engine upon the fuel injected.

A further object of the invention is to provide a manual control forregulating the actuation of the fuel injection devices of acompression-ignitionengine so that during starting, fuel charges will beinjected into the combustion spaces when the compressed air charges are.at substantially their highest compression, and under a pressure suchthat sufiicient penetration occurs to quickly cause a thoroughintermingling of the fuel mixtill another object of the invention is toprovide a manual control which can be actuated during the starting of anengine of the compressionignition type to bring into action a fastermoving fuel pump actuating cam mechanism at a later time in thecompression stroke of the engine operation.

Theseand other objects of the invention will appear from the followingdescription taken in connection with the drawings, which form a part ofthis specification, and in which:

Fig. 1 is a rear elevational View of a radial engine, partialy brokenaway and partially in section to show a fuel injecting device and itsactuating mechanism;

Fig. 2 is an elevational view showing the fuel gine cylinder.

Referring now to the drawings by characters of reference, 10 representsgenerally the crank case of a compression-ignition type of internalcombustion engine from which nine air-cooled cylindersll extendradially, the cylinders being secured under compression around the wallof the crank case by rings, one of which is indicated at 12. Thecylinders are formed with an integral dome 13 and secured upon each ofthe domes is a head 14. Each of" the associated heads and domes isformed with a single Venturi passage 1 leading into the interior of: theassociated cylinder, such passages serving as both the air inlet andtheexhaust outlet for the combustion chambers between the cylinder domesand the pistons 16. In order to control the passages 15, there isassociated with each a valve 17 which is normally closed by a pluralityof springs 18 and opened by conventional mechanism which includes a pushrod 19 extending into the crank case.

A diaphragm. or internal Wall 20 is secured within the crank case and isformed with a central opening in which is arranged a bearing 21 forsupporting one end of the crank shaft 22,

the crank shaft projecting axially through the crank case. Arrangedin arelation substantially parallel to the diaphragm is; a detachable rearwall 23 which closes the open end of the crank case, and detachablysecured to the rear wall is 3 a starting device, indicated generally at24, which is preferably of the inertia type as illustrated'in Patent No.1,739,469, issued December 10, 1929, to R. P. Lansing. Such startingdevice is provided with a reciprocable jaw 25 which projects into thecrank case in alignment with the rear end of the crank shaft, so. thatit can be moved manually into a drivingrelation therewith.

The engine illustrated is of the compression ignition, or Diesel type,which operates on a four-stroke cycle, air charges being drawn into thecylinders through the passages 15 upon the suction strokes of thepistons, during which time the valves 17 are mechanically held open. Thevalves are next closed and the compression strokes then occur, andduring the compression strokes charges of liquid fuel or oil areinjected into the air-compressed charges under a high pressure and in anatomized condition such that the mixture thereof with the compressed airwill form a readily combustible charge. There is associated with eachcylinder a fuel injection device which consists generally of a nozzleportion 26 and a pump portion 27, the nozzle portion being securedrigidly to the cylinder and arranged to project through the wall thereofso that the fuel charges can be injected directly into the interior ofthe cylinder.

Each nozzle consists of a barrel 28 having a detachable end 29 whichextends through the associated cylinder wall and is formed with aconical outlet opening in which the valve head 30 is associated. Thevalve stem 31 is arranged to be moved into engagement with the stopmember 32 by a spring 33, and such stop member is adjusted to preventthe valve from entirely closing. The barrel 28 is formed with adownwardly extending neck portion which is provided with a passage 34leading to the hollow chamber in the barrel through which the valve rodextends.- Such nozzle neck is screwed into the casing 35 of theassociated pump unit and bears against a ring spacer 36 which maintainsthe pump barrel 3'? in position within the casing 35, there being a pairof spring-pressed valves 38 associated with the ring member and'thebarrel to prevent liquid fuel returning to the pump structure from thenozzle structure. A plunger 39 is arranged to reciprocate within thepump barrel and a fuel inlet manifold 40 communicates with all of thepumps, there being unions 41 in the manifold structure associated onewith each of the barrels, and ports 42 extend through the casing and thebarrel to establish communication between the fuel feeding manifoldunions and the interior of the valve. Such ports are controlled by theposition of the plunger, so that when the plunger uncovers the ports 42liquid fuel is moved into the pump barrel and the nozzle completelyfilling the chambered portions therein. The pump plungers are moved intheir injection strokes by mechanism, which will be hereinafterdescribed, and during such movement they close the ports 42, theirstroke after closing such ports determining the quantity of fuel whichis displaced from the nozzle into the cylinder.

It will be seen that the speed of the plunger movement determines thedegree of pressure at which the fuel charge is injected. The effectivestroke of the plungers will force fuel past the valves 31 and from thenozzles in a manner such that the fuel charges are directed into thecylinders in a conical spray. The air inlet passages are formed andarranged so that they cause r0- tation of the air in the cylinders andsuch rotation continues during the following compressionstroke of thepiston, the fuel charges being sprayed into such compressed rotating aircharges. e

The degree of fuel atomization and the extent of the pressure at whichit is injected determine the degree of the intermingling of the oil withthe air and, therefore, it is necessary that there be sufficientinjection penetration and atomization to cause a uniform distribution ofthe fuel in the compressed'air charges if efficient engine operation isto result. It is also necessary that the atomization and penetration ofthe air by the fuel oil be of a certain character if combustion is to beattained when the cylinders are cold, as they are when starting. Withthe type of injection mechanism described, in which the fuel pressurevaries in accordance with the crank shaft speed, there is difficultyexperienced when turning the crank shaft at a slow speed in starting toproduce a suflicient pressure behind the fuel charges because of theconsequent slow movement of the fuel pumps which is not sufficient tocause the fuel atomization and penetration of the compressed air chargesrequired to produce a mixture which will support combustion.

This invention has to do particularly with mechanism for injecting fueloil in an atomized condition and at a suiiicient pressure to cause anintermingling with the compressed air in the cylinders such thatignition will readily result when the crank shaft is being slowly turnedthrough the application of a starting device. To this end, I utilize theregular fuel injecting mechanism for the normal running operation of theengine and provide an auxiliary actuating mechanism therefor which iseffective only during the application of the starting mechanism to thecrank shaft. This auxiliary actuating mechanism is made efiectivemanually and is placed in ineifective relation automatically when thestarting device is released from the crank shaft. In

carrying out such invention, I propose that the liquid fuel charges willbe injected, during the turning of the crank shaft by the startingdevice, at a pressure which will cause the fuel to penetratesubstantially to the center of the cylinder and in a finely atomizedcondition so that one rotation of the compressed air in the cylinderwill cause a uniform distribution therein of the atomized liquid fuel.

Under normal running operation, crank shaft actuated mechanism isprovided for causing the pump plungers to move in their injectionstrokes, and such mechanism is returned to a position causing uncoveringof the ports 42 by the coil spring 43. A fuel plunger push rod 44extends through the crank case and has associated therewith a lever 45which is pivotally connected with a link 46 carried between a regulatingring 47 rotatably mounted within the crank case. The ring 4'7 can beactuated through the association of a tooth segment 48 with a rack 49which is fixed to the ring, the segment being rotated by means of theshaft 50 which is in turn actuated through suitable mechanism connectedwith the lever 51. Associated with each of the levers 45 is a slipper orrock lever, as shown at 52, 53 and 54, each being carried by individualshafts 55 supported by the diaphragm and the rear casing cover 23. Thefree ends of the rock levers are formed with a curved face against whichthe associated lever 45 is maintained by means of the adjustable ring 47and the connecting links 46, so that upon movement of the levers 45,lengthwise of the slippers, the effective stroke of the pump plungerscan be simultaneously adjusted.

Arranged interiorly of the pivoted slippers 53, for actuating the sameto cause an injection stroke of the pump plungers, is a cam 56 which isprovided with four lobes 5'7, 58, 59 and 60.

A cam 60 is formed with an internal gear 61 crank shaft. -described,is'related'so that rotation of the'crank shaft will cause rotation 'ofthe cam "56 in a direction oppositeto that of the crankshaft and 5 atone-eighth the speed" of rotation'thereof.

mechanismisassociated with the cams'56 and'SO' This arrangement" ofgearing, just The rotation of the cam 56 is such that upon eachtworevolutions of the'crank shaft, the lobes 57, 58, 59 and 60 will causeone actuation of eachof the nine slippers associated with thefuel'injection 'mechanisms. 'The'c'am 60"is also provided with a 'seriesof 'four lobes -'72, one of which'isshown -in Fig. 1, 'foractuatingslippers 73,mo'unted on theshafts 55, withwhi'ch the valve pushrods 19 are associated so that'durin'g the suctionand exhaust strokesofthe pistons, the valves areheld open thereby.

As before stated, [have found that'with the fuel injection mechanismdescribed, sufficient penetrationof the=compressed air charges in thecylinders and a desirable atomization'of the fuel is'attained duringrunning operationof the ening theair compression when the bestefficiency will result, I provide an auxiliary mechanism for actuatingthe slippers associated with each of the injection devices, and to thisend I provide each of the fuel mechanism slippers with an extendedportion 74 so that they can be actuated by a single lobe cam 75 which isarranged to be driven 'with'and at-crank shaft speed. Thiscam, runningat crank shaft speed, 'will "move eight times as fast as the regularfuel actuating cam 56 and, consequently, will cause a much faster strokeof the pump plungers than would be caused =by the cam 56, thus resultingin a highly increased pressure and an atomization beyond that whichwould be attained with the cam '56 in effective position when the crankshaft is turning at slow speeds. In addition, the cam 75 is arranged tocause an injection stroke of the plungers at a later time 'duringthe aircompression stroke than that which is caused by the cam56. The cam 75 ispreferably arranged to cause fuel injections just shortly before thepistons reach the top of their compression strokes, while the cam 56 ispreferably arranged during engine operation so that the fuel injectionsoccur in a range between 40 to 20 degrees before the pistons reach topcenter on their compression stroke. "I have found that when starting,this delay in timing and the provision of a pressure behind the fuelcharge will cause a substantial penetration of the compressed aircharges in a well atomized condition, which materially assist the quickstarting of engines of the compression-ignition type operating on liquidfuel of low volatility, and as a result, very little turning of thecrank shaft is required to cause combustion.

The cam 75 is secured to the crank shaft'by screws 76. The cam 56 isprovided with a hub portion 77 which extends rearwardly and upon whichthe hub of the cam 60' is rotatably mounted.

Only one of the fuel device actuating cams is effective at a time, andmanually controlled for "regulating the position of the cam 56Singularly of the crankshaft so that either the cam 56hr 75 iseffective. A'c'ontrol sleeve 78 is partiallytelescope'd between a flange79 extending rearwardly from the cam 60' and the rear end "of the hub 77, such sleeve having peripheral helical teeth 80 which engage similarteeth formed interiorly of the flange 79. The front end of the sleeve isprovided with helical splines 81 which mesh with helical splines '82formed in the peri'phery of a coupling member 83. Such couplingnier'nber surrounds the rear end of the cam hub 77 and is provided withhelically extending splines 84 which mesh with the helical -splines 85formed on the periphery of the rear end of the hub 77. A nut 86 isscrewed upon the'end of the crank 'shaft'for axially retaining thecoupling nie'r'nber s3, y g

In order to control the position of the sleeve 78, I provide a yoke 87which engages therewith, such yoke being actuatedby the rod 88 extendingthrough the end Wall of the casing. A stop member 89 is fixed to the rodand a spring 90 is arranged within a recess in the end wall to exertpressure against the stop member normally tending to cause movement ofthe yoke 87t o its rearmost position.

When the yoke and control sleeve 78 are in their real-most position, asshown in Figs. 1 and 3, the cam 56 is disposed angularly upon the crankshaft and relative to the cam 60 so that the lobes thereon will beeffective to actuate the fuel injection mechanism. The lobes 57, 58, 59and 60 are of suffici'ent'lehgth Such that they'maimain therockerlevers, which they have actuated, in an elevated position untilsuch time as the single lobe on the cam 75 has passed thereunder, thusmaking the cam 75 ineffective. As the cam '75 moves at crank shaft speedand in the same direction with the crank shaft, the timing is such thatthe rocker levers will be in a raised relation through associationtherewith of the cam 56 so that regardless or an eight times fasterspeed, the cam 75 will be ineffective. It will'be're'menibered that thecam 56, when in this position, is arra'hg'd to actuate the rocker leversbetween 40mm 20 degrees before thepistons reach top center, dependingupoh th'e adjustment of the levrs45, while the starter cam 75 isfixedang'ularly "oh the crank shaft to be efiective approkimatelytndegrees'bf'ore the pistons reach top center on'their'co'rhpre'ssiohstrokes. It will also be seen that inseam 56 is driven from the cam 60through the control sleeve 78 and the coupling83 sdthat it will rotateinan integral relation therewith. I

As the yoke 87 is moved forwardly through actuation of the rod 88, thehelically splined ass'ociation of the sleeve 78 with the flange 79 andthe cam 60 will cause rotation of the sleeve and a similar rotation ofthe coupling 83 and of the cam 56, so that in this manner theangular-pdsition of the cam 56 upon the crank shaft will be changedtomove the lobes thereon so that they will be moved to ineffectiveposition as shown in Fig. 2, andpreferably where they would be'eifectivewhen the pistons reach top center of the compression strokes. Withsuch'control mechanism, the moving of the cam 56 angularly relative tothe crank shaft into an ineffective position and holding the same insuch relation, willinaketh'e cam 75 effective. As the cam 75 the speedat which the fuel injectingmechanism is actuated will be materiallyincreased over that which would result if the cam 56 were effective.

As before explained, the control sleeve 78 is normally in its rearmostposition as shown in Figs. 1 and 3, and when it is desired to start theengine, the rod 88 is pushed forward moving the control sleeve 78 as faras possible, which will. rotate the cam 56 angularly upon the crankshaftinto an ineffective position, thusmaking the cam effective. As thesleeve is moved axially, it will be caused to rotate because of thehelically splined association with the cam member 60', theinertia of theelements geared with such cam member beinggreater than that of the cammember 56. The crank shaft has a jaw 91 at the end thereof which thestarter jaw 25 is moved into engagement with and rotation is imparted tothe crank shaft through this connection, with. the control ring 78 inits forward position. Dur-- ing such relation, the cam '75 is rotatingat suchv a speed that itwill shield the slippers associated. with thefuel injection mechanism from being actuated by the lobes on the cam56.: Rotation of the crank shaft by the starter, with the cam 75-effective, will cause a much higher pressure to be exerted against thefuel charges injected than if the cam 56 were effective, and with thecrank shaft turning at a relatively slow speed, the pres-- sure andatomization resulting from actuation of the fuel injection mechanisms bythe cam 75 will cause the fuel charges to penetrate to substantially thecentral portion of the cylinders so that a homogeneous mixture with thecompressed air rotating therein will occur within a very few degrees ofthe crank shaft rotation. In. this manner, while the fuel charges areinjected only, ten degrees before top center of the compression strokesof the pistons, the proper mixing of the fuel with the air andcombustion will occur before the pistons reach top center. Thismechanism materially aids in the starting of a compression-ignitionengine because the proper mixture of the fuel must be present in orderto cause the initial explosions which will ultimately heat the cylinderssufiiciently to produce se1fignition.

While I have herein described in some detail. a specific embodiment ofmy invention, which I deem to be new and advantageous and mayspecifically claim, I do not desire it to be understood. that myinvention is limited to the exact details of the construction, as itwill be apparent that changes may be made therein without departing fromthe spirit or scope of my invention.

What I claim is: y

1. In a compression-ignition engine, a pressure injection device forintroducing liquid fuel into compressedair charges in the engine, acrank shaft, a cam for actuating the injection device, an air valveactuating cam. a gear fixed to the injection device actuating cam,reduction gearing intermediate the crank shaft and the air valveactuating campan axially movable driving sleevemeshing with the gearfixed to the cam and having a helically splined association with the airvalve actuating cam, said driving sleeve being movable axially to changethe relation of the fuel injection device actuating cam angularly of thecrank shaft, manually operable means for shifting the sleeve in oneaxial direction, and spring means opposing the manual movement of thesleeve.

2. In a compression-ignition engine, a pressure injection device forintroducing atomized liquid fuel into compressed air charges in theengiue, a crank shaft, a single lobe cam for actuating the device fixedto the crank shaft, a multiple lobe cam for actuating the device androtatably associated with the crank shaft adjacent the fixed cam, an airvalve actuating cam, a reduction driving mechanism between the crankshaft and the air valve actuating cam, a driving connection including amovable sleeve, helically splined to the air valve actuating cam andgeared to the multiple lobe cam, the movement of the sleeve relative tothe cams causing the multiple lobe cam to be rotated to place the. lobesthereof in effective or ineffective relation with the fuel devicethrough operation in advance of or behind the fixed cam loberespectively, means automatically urging the sleeve into one extremeposition, and a manually actuated means for shifting the sleeve into itsother extreme position.

3. In a radial cylinder compression-ignition engine, a pressureinjection device associated with each cylinder for introducing atomizedliquid fuel into compressed air charges therein, a crank shaft, a singlelobe cam fixed to the crank shaft for actuating the devices, a multiplelobe cam for actuating. the devices rotatably associated with the crankshaft, an air valve actuating cam, reduction gearing between the crankshaft and the air valve actuating cam, a shiftable driving connectionbetween the multiple lobe cam and the air valve actuating cam, saiddriving connection being shiftable into two positions to place themultiple cam lobes in effective or ineffective relation with theinjection devices, manually operable means for shifting the'drivingconnection, :and spring means opposing the manual movement of thedriving connection.

4. In a compression-ignition engine, a pressure injection device forintroducing atomized liquid fuel into compressed air charges in theengine, a crank shaft, a single lobe cam for actuating the device fixed.to the crank shaft, a multiple lobe cam for actuating the device androtatably associated with the crank shaft, only one of said cams beingeffective at a time, an air valve actuating cam, a circular flangeextending laterally from the air valve actuating cam. said flange havingan internal helical spline, a gear fixed to the multiple lobe cam,reduction gearing between the crank shaft and the air valve actuatingcam, a sleeve meshing with the gear fixed to the multiple lobe cam andthe splined flange of the air valve actuating cam, and manual means formoving the sleeve axially.

5. In a compression-ignition engine, a pressure injection device forintroducing atomized liquid fuel into compressed air charges in theengine, a crank shaft, a single lobe cam for actuating the device fixedto the crank shaft, a multiple lobe cam for actuating the device androtatably associated with the crank shaft, only one of said cams beingeffective at a time, an air valve actuating cam having a helical spline,a gear fixed to the multiple lobe cam, reduction gearing between thecrank shaft and the air valve actuating'cam,

a sleeve member meshing with the gear fixed to the multiple lobe cam andhaving a helical spline meshing with the helical spline on the air valveactuating cam. a yoke associated with the sleeve,

manually operable means connected to the yoke for moving the sleeveaxially in one direction, and a spring associated with said means formoving the yoke in the opposite direction.

6. In a compression-ignition engine, a pressure injection device forintroducing atomized liquid fuel into compressed air charges in theengine, a crank shaft, a single lobe cam for actuating the injectiondevice fixed to the crank shaft, a multiple lobe cam for actuating thedevice and rotatably associated with the crank shaft, only one of thefuel injection cams being effective at a time, an air valve actuatingcam having a helical spline, a gear fixed to the multiple lobe cam,reduction gearing between the crank shaft and the air valve actuatingcam, a sleeve member meshing with the gear fixed to the multiple lobecam and having a helical spline meshing with the helical spline on theair valve actuating cam, a yoke associated with the sleeve, a manuallyoperable rod for moving the yoke to cause axial movement of the sleeve,and a spring associated with the rod to exert pressure against movementof the rod.

7. In a compression-ignition engine, a pressure injection device forintroducing liquid fuel into compressed air charges in the engine, acrank shaft, a cam for actuating the injection device to introduce fuelinto the air charges, an air valve actuating cam, reduction gearingconnecting the air valve cam with the crank shaft, a driving connectionbetween the two cams including an axially movable sleeve helicallysplined between the cams, the axial movement of the sleeve rotating thefuel cam relative to the air cam, a spring for holding said sleeve inone extreme axial position, and manually operable means for moving andholding the sleeve in its other extreme axial position.

8. In a compression-ignition engine, a pressure injection device forintroducing liquid fuel charges into compressed air charges in theengine, a crank shaft, a cam for actuating the injection device, an airvalve actuating cam, a gear fixed to the injection device actuating cam,reduction gearing intermediate the crank shaft and the air valveactuating cam, an axially movable driving sleeve helically splined withthe gear fixed to the cam and helically splined to the air valveactuating cam, said sleeve being movable axially to change the relationof the fuel injection device actuating cam angularly of the crank shaft,and manually operable means associated to shift the sleeve in an axialdirection.

9. In a compression-ignition engine, a pressure injection device forintroducing atomized liquid fuel into compressed air charges in theengine, a crank shaft, a single lobe cam fixed to the crank shaft in arelation to actuate the injection device,

a multiple lobe cam for actuating the device, said multiple lobe cambeing rotatably associated with the crank shaft adjacent the fixed cam,an air valve actuating carn, reduction gearing between the crank shaftand the air valve actuating cam, a driving connection between the airvalve actuating cam and the multiple lobe cam including an axiallymovable sleeve helically splined to the air valve cam and to themultiple lobe cam, the axial movement of the sleeve rotating themultiple lobe cam to place the lobes thereof in advance of or behind thefixed cam lobe whereby they are in effective or ineffective relationwith the fuel injection device, manually operable means for moving thesleeve axially, and spring means opposing the manual movement of thesleeve.

10. In a compression-ignition engine, a pressure injection device forintroducing atomized liquid fuel into compressed air charges in theengine, a cam for actuating the fuel injection device, an air valveactuating cam, mechanism driving the air valve actuating earn from amoving part of the engine, driving mechanism between the cams includingan axially movable sleeve helically splined to the air valve cam,manually operable means for shifting the sleeve, and spring meansopposing the manual shifting of the sleeve.

11. In a multi-cylinder combustion engine of the compression-ignitiontype, a pressure injection device associated with each cylinder forintroducing atomized liquid fuel into compressed air charges in thecylinders, a crank shaft, a cam fixed to the crank shaft to actuate thedevices substantially at the highest compression of the air charge, aslower driven cam for actuating the injection devices in advance of thefast cam injection, only one of the cams being effective at a time andthe lobe portion of the advanced cam masking the lobe portion of theretarded cam from operative engagement with the injec- 5 tion devices,an air valve operating cam, means for driving the slower cam from theair valve cam including an axially adjustable sleeve in helicallysplined relation with the air valve cam, a manually operable controlmember associated to axially move the sleeve to shift the slower camangularly into retarded position relative to the fast cam, and automaticmeans for urging the control member in a position to maintain the slowercam in advanced relation relative to the fast cam.

CLARENCE H. WIEGMAN.

